export function Base64ToBlob(urlData) {
  // 去掉url的头，并转换为byte
  const bytes = window.atob(urlData.split(",")[1]);

  // 处理异常,将ascii码小于0的转换为大于0
  const ab = new ArrayBuffer(bytes.length);
  const ia = new Uint8Array(ab);
  for (let i = 0; i < bytes.length; i++) {
    ia[i] = bytes.charCodeAt(i);
  }
  return new Blob([ab], {
    type: "image/png"
  });
}
